Hazardous location cooling system and method for use thereof

ABSTRACT

An embodiment includes a cooling unit, including: a housing configured to attach to an enclosure opening in a sealed manner, where the enclosure houses heat generating electrical equipment; the housing including: a first ambient side area including a compressor, condensing coils, and an ambient air intake and outlet; a first enclosure side area situated above the first ambient side area and including an electrical box that includes one or more relays and a digital controller; a second enclosure side area extending along the rear side of the housing and communicating with the first enclosure side area, including an impeller, an enclosure air intake, an enclosure air return, and evaporator coils in fluid communication with the condenser coils; and a second ambient side area including an impeller and one or more hot air exhausts; where all components of the cooling unit are non-sparking and non-arcing; and where the first and second ambient side areas are sealed off from the first and second enclosure side areas. Other embodiments are described and claimed.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. patent application Ser. No.16/071,061, filed 18 Jul. 2018, which is a national stage entry of PCTapplication number PCT/US18/13442, filed on Jan. 12, 2018, which claimsthe benefit of U.S. provisional patent application Ser. No. 62/446,041,filed on Jan. 13, 2017, the contents of each prior application areincorporated by reference herein.

FIELD

The subject matter disclosed herein relates to closed-loop enclosurecooling systems and related techniques. Some of the subject matterdisclosed herein relates to closed-loop cooling systems mounted toanother enclosure and used for cooling electronics within the enclosurewithin a hazardous environment.

BACKGROUND

Closed-loop enclosure cooling systems (air conditioners) arespecifically designed to mount on to electronic enclosures, e.g., acabinet that contains heat generating electronic components, and removeheat without letting outside air into the sealed enclosure. This type ofcooling is typically used to cool electronic equipment housed inside aNational Electrical Manufacturers Association (NEMA) rated enclosure,which protects sensitive electronics from dust, splashing liquids andproduction residues. Such enclosures are used in a variety ofindustries, including telecommunication, industrial automation, oil andgas production, pharmaceutical, food and beverage, and wastewater.

In a closed-loop system, the heated enclosure air is drawn into the airconditioner. Heat and moisture are removed as the heated enclosure airpasses through an evaporator coil. The conditioned air is forced backinto the enclosure. In a closed-loop system, the integrity of theenclosure is maintained.

BRIEF SUMMARY

In summary, one embodiment provides a cooling unit, comprising: ahousing configured to attach to an enclosure opening in a sealed manner,where the enclosure houses heat generating electrical equipment. Thehousing comprises: a first ambient side area including a compressor,condensing coils, and an ambient air intake and outlet. The housingfurther includes a first enclosure side area situated above the firstambient side area. The first enclosure side area includes an electricalbox that includes one or more relays and a digital controller. In anembodiment, all components of the electrical box are non-sparking andnon-arcing, and do not require purging of hazardous air.

In an embodiment, the housing further includes a second enclosure sidearea extending along the rear side of the housing and communicating withthe first enclosure side area. The second enclosure side area includesan impeller, an enclosure air intake, an enclosure air exhaust, andevaporator coils in fluid communication with the condensing coils.

In an embodiment, the housing further includes a second ambient sidearea, which includes an impeller and one or more hot air exhausts. Thefirst and second ambient side areas are sealed off from the first andsecond enclosure side areas.

In an embodiment, all components of the cooling unit are non-sparkingand non-arcing, and are acceptable for use in a hazardous environment.The components do not require purging of hazardous air. In anembodiment, one or more of the components of the electrical box are madesafe for hazardous environment use via sealing, e.g., with an epoxy, useof solid state devices, or are nonincendive components.

In an embodiment, the first enclosure side area comprises a first plateonto which one or more components of the electrical box are adhered orattached, and the first plate sits atop a second plate that seals thefirst enclosure side area off from the first ambient side area. In anembodiment, the first and second plates define an air gap into whichenclosure air circulates, cooling one or more components of theelectrical box. The first plate may include a heat sink to manage heat,e.g., generated by components of the electrical box.

In an embodiment, the electrical box includes power and dataconnections, e.g., an ethernet connection. These power and dataconnections may be used to remotely monitor or control the airconditioner, e.g., report on an alarm condition, respond to remotecommands to adjust settings, etc.

In an embodiment, a connection is provided for fitting to a purge systemof the enclosure. An embodiment comprises a purge tube extending fromthe fitting and terminating within the first enclosure side area.

In embodiment, the housing is about 9.5 to about 17.75 inches in width.

In an embodiment, a filter is positioned to filter air that transitsthrough the ambient air intake.

In an embodiment, the second ambient side area comprises three hot airexhausts positioned on the front, left and right sides of a rectangularhousing. A diverter plate attaches to any of the three hot air exhausts.More than one diverter plate may be provided and attached to more thanone of the hot air exhausts.

In an embodiment, a digital controller is disposed within a rear,enclosure facing surface of the rectangular housing. The digitalcontroller is nonincendive and may be exposed to hazardous air. In anembodiment, the digital controller may be located elsewhere, e.g., on afront, ambient side of the air conditioner.

In an embodiment, the second enclosure side area comprises a water draintherein. The water drain is disposed in a bottom plate of a drain pan ofthe rectangular housing. A ball and drain tube form an assembly, and areincluded so that the drain tube is situated at the drain.

An embodiment provides a method of installing a closed loop cooling unitto an enclosure for hazardous location cooling. In an embodiment, themethod includes attaching the cooling unit to the enclosure such that anenclosure side of the cooling unit conducts heated air from theenclosure over cooling coils disposed within an elongated, rearenclosure side area of the cooling unit, which faces the enclosure. Theattaching step includes arranging an enclosure air intake and return ofa rear face of the elongated, rear enclosure side area to conduct heatedair from the enclosure over the cooling coils. The cooling unit can thenbe operated to conduct heated air from the enclosure over components ofan electric box of an upper enclosure side area of the cooling unithaving non-sparking, non-arcing components disposed therein. All ambientside areas of the cooling unit are segregated from the elongated, rearenclosure side area and the upper enclosure side area of the coolingunit.

The foregoing is a summary and thus may contain simplifications,generalizations, and omissions of detail; consequently, those skilled inthe art will appreciate that the summary is illustrative only and is notintended to be in any way limiting.

For a better understanding of the embodiments, together with other andfurther features and advantages thereof, reference is made to thefollowing description, taken in conjunction with the accompanyingdrawings. The scope of the invention will be pointed out in the appendedclaims.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1(A-B) illustrates an example closed-loop enclosure cooling systemaccording to an embodiment.

FIG. 2 illustrates an example closed-loop enclosure cooling systemaccording to an embodiment.

FIG. 3 illustrates a top view of an example closed-loop enclosurecooling unit according to an embodiment.

FIG. 3A illustrates a cross sectional view of the example view of FIG.3.

FIG. 4(A-D) illustrates an example closed-loop enclosure cooling unitaccording to an embodiment.

FIG. 5 illustrates a rear view of an example closed-loop enclosurecooling unit according to an embodiment.

FIG. 5A illustrates a detail view of a drain assembly illustrated inFIG. 5.

FIG. 6 illustrates an example method according to an embodiment.

DETAILED DESCRIPTION

It will be readily understood that the components of the embodiments, asgenerally described and illustrated in the figures herein, may bearranged and designed in a wide variety of different configurations inaddition to the described example embodiments. Thus, the following moredetailed description of the example embodiments, as represented in thefigures, is not intended to limit the scope of the claims, but is merelyrepresentative of those embodiments.

Reference throughout this specification to “embodiment(s)” (or the like)means that a particular feature, structure, or characteristic describedin connection with the embodiment is included in at least oneembodiment. Thus, appearances of the phrases “according to embodiments”or “in an embodiment” (or the like) in various places throughout thisspecification are not necessarily all referring to the same embodiment.

Furthermore, the described features, structures, or characteristics maybe combined in any suitable manner in one or more embodiments. In thefollowing description, numerous specific details are provided to give athorough understanding of example embodiments. One skilled in therelevant art will recognize, however, that aspects can be practicedwithout one or more of the specific details, or with other methods,components, materials, etc. In other instances, well-known structures,materials, or operations are not shown or described in detail to avoidobfuscation.

In this detailed description, an “area” and a “compartment” are usedinterchangeably, unless specifically indicated otherwise.

In an embodiment, all components of the air conditioner are non-sparkingand non-arcing, e.g., formed of nonincendive components, solid statecomponents, or sealed components. Therefore, the entire unit is capableof use in a hazardous location.

The present disclosure provides a cooling system and method for use thatis designed for use in hazardous locations. In particular, an embodimentof the present disclosure is designed for use in hazardous locationsclassified as Class I, Division 2, Groups A, B, C, & D and may beembodied, at least in part, commercially as part of the EvolutionSeries' of products offered by ICE QUBE, INC. of Greensburg, Pa., USA.In an embodiment, a cooling system is designed for use in locationsclassified as Zone 2, IIC rated (ATEX IECEx Zone 2). In an embodiment,the cooling system comprises a closed-loop circulation design thatprotects equipment from air-borne dust and contaminants, which mayhinder a customer's other equipment operations and cause unnecessarydowntime. Various embodiments may be configured in different sizes,power configurations, and BTU capacities to provide air conditioningsystems suitable for various needs. Embodiments may be designed asenclosure top or side mount packages. A side mount cooling unit isillustrated and described by way of example; however, this is anon-limiting example. Any directional terms (e.g., upper, rear, etc.)may be easily translated to the appropriate term given the nature of theimplementation.

In addition, despite the fact that embodiments of the present disclosureare described in connection with use in hazardous locations, there is noreason that any of the embodiments could not also be used as ageneral-purpose cooling system. Such a design provides for customerflexibility when using the cooling system in various types of locations.

An embodiment overcomes the limitations of the prior art by utilizingall non-sparking, non-arcing component parts, which may includeencapsulated, solid-state, nonincendive, and/or hermetically sealedcomponent parts. These methods of protection render the resultantcomponents incapable of releasing enough electrical or thermal energy toignite any hazardous gases, vapors, or liquids that may be found in theenvironment where the cooling system is operating. An embodimenttherefore does not contain any ignition sources and is nonincendive, asthat term is commonly understood in the art. As a result, thenonincendive system does not need to be used with a purge system whenmounted to an enclosure having potentially hazardous enclosure side air,which is a traditional mechanism for protecting ignition sourcecomponents in cooling systems used in hazardous locations.

Some of the other novel features of the cooling device described hereininclude a compact design to fit on smaller cabinets or enclosures. Inone embodiment, an 11″ (inch) narrow mounting width is provided.However, other sizes are possible for a cooling device according tovarious embodiments. For example, in one embodiment the air conditionerhousing is about 20.06″ in height, about 9.85″ in width, and about11.00″ in depth. In another embodiment, the air conditioner housing isabout 28.58″ in height, about 11.31″ in width, and about 14.15″ indepth. In yet another embodiment, the air conditioner housing is about38.58″ in height, about 11.31″ in width, and about 14.15″ in depth. In afurther embodiment, the air conditioning housing is about 44″ in height,about 18″ in width, and about 20″ in depth.

A multi-directional condenser air discharge, which is adjustable in atleast four different configurations, is provided. A digital controllerwith programmable temperatures, which can be installed either on thefront or rear of the system, is provided. In one embodiment, the digitalcontroller is located within a hazardous location electrical box of thecooling system. In an embodiment, an alarm is provided and can beconfigured to alert a user when the temperature of component(s) is/areabove or below certain set limit(s), when the cooling system has beenturned off, or when the cooling system malfunctions or operates at apredetermined level or condition.

An embodiment comprises a combination of systems that functionsimultaneously to maintain environmentally friendly conditions forequipment within the enclosure. The major thermal related systemscomprise a closed-loop cold air supply stream, a heat rejection airstream, and a vapor-compression refrigeration system. In an embodiment,the cooling system itself may be further divided into an evaporatorcompartment (housing component parts configured to remove heat from theenclosure), a condenser compartment (housing component parts configuredto compress refrigerant gas and vapor for return to the evaporatorcompartment), and an electrical box housing the electronic componentsthat control the cooling system.

In an embodiment, the vapor-compression refrigeration system comprises aquiet, energy efficient rotary compressor configured to circulateenvironmentally friendly NON-CFC refrigerant. A purpose of thiscompressor is to transfer heat laden refrigerant from the evaporator,located within the closed-loop cool air system (the evaporatorcompartment), to a condenser, located in the warm air system (thecondenser compartment). In the warm air system, air is circulated fromthe ambient surrounding the enclosure housing the cooling system,through a filter, and across the warm air system heat exchanger.

In one embodiment, a recessed pull-out filter may be used to filterambient air as it enters the system. The filter does not require aseparate filter holder. Such a configuration enables the filter to beremoved without the use of tools. Heat from the enclosure is transferredfrom the warm air heat exchanger into the warm air stream and dissipatedto the ambient air.

The enclosure air that is drawn into the cooling system brings with itunwanted heat and humidity from inside the enclosure. Heat and humidityis then removed by a heat exchanger (evaporator) located within theevaporator compartment of the cooling system. This heat exchanger ispart of the vapor-compression refrigeration system.

In one embodiment, a heat exchanger of the present disclosure may beconfigured to have only two moving parts. These parts may comprise oneor more maintenance-free impellers or blowers, which are used to moveair over the heat exchanger coil. An enclosure impeller moves hot airfrom the top of enclosure, through the heat exchanger coil where theheat is dissipated and the cool air returns to the bottom of theenclosure. An ambient impeller moves air through a coil where the heatfrom the enclosure is absorbed and dissipated to the ambient air.

The description now turns to the figures. The illustrated exampleembodiments will be best understood by reference to the figures. Thefollowing description is intended only by way of example and simplyillustrates certain selected example embodiments.

Referring to FIG. 1A, a side view illustrates a closed-loop coolingsystem that includes an air conditioner 102 that cools heated air of anenclosure 101, which in turn includes heat generating components, e.g.,electrical equipment. The air conditioner 102 is attached to theenclosure 101, e.g., at an opening 103. The air conditioner 102 isclosed-loop because it includes an enclosure side compartment,illustrated as a rear compartment (left side in FIG. 1A), and an ambientside compartment, illustrated as a front compartment (right side in FIG.1A). This permits the air conditioner 102 to cool air of the enclosure101 without mixing the returned, conditioned air with ambient air, whichonly interfaces with components in the ambient side compartment.

Conventionally, the enclosure side compartment of the air conditioner102 is purged to ensure that the components of the enclosure sidecompartment are safe for use in a hazardous environment. For example, apurge system provides pressurized air to the enclosure side compartment,purging out any hazardous air that may envelope the components of theenclosure side compartment. However, because all components of the airconditioner 102 are non-sparking and non-arcing, purging is notrequired.

In FIG. 1B, a perspective view of the air conditioner 102 is provided.Here, the front of the air conditioner 102 is illustrated in perspectiveview, i.e., the front side faces away from the enclosure 103. Theambient airflow is illustrated, where ambient air enters through an airfilter 130 that covers an air intake on the right side of the airconditioner 102 (refer to FIG. 4D). The air conditioner 102 includesambient air outlets or exhausts, two of which are indicated in FIG. 1Bat 132, 133, and a diverter plate 134 that may be attached to any of theair outlets or exhausts 132, 133. A digital controller 107 is providedfor controlling the air conditioner 102. The digital controller 107 maybe located on the front face, as illustrated in FIG. 1B, or anotherface, e.g., the rear of the air conditioner 102, as further describedherein.

Referring to FIG. 2, an embodiment provides an air conditioner 202 thatincludes non-sparking, non-arcing electronics components in anelectrical box exposed to the enclosure air, avoiding the need for apurge system. In the example of FIG. 2, a closed-loop cold air supplystream circulates cold air from the cooling system 202 to an enclosure201, which is configured to house various heat generating electroniccomponents. In an embodiment, the cooling system 202 includes ambientside compartments and enclosure side compartments, as further describedherein.

In the example illustrated in FIG. 2, the air conditioner 202 isgenerally rectangular in shape and includes a housing that definesvarious compartments/areas containing functional components. By way ofspecific example, illustrated is an air conditioner 202 that is sealedto an aperture or opening 203 of an enclosure 201. The air conditioner202 includes a first ambient side compartment 204 that contains acompressor and condenser coils (the covers of the first compartment 204have been removed in FIG. 2 for illustration of the components therein).

The air conditioner 202 includes a lower ambient side compartment 205that includes an impeller 210 to draw ambient air into the ambient sidecompartment 205 (e.g., via air filter 430 and air inlet 431 illustratedin FIG. 4D). FIG. 2 provides for the location of a condenser impeller210 in the lower section of the condenser compartment 205 of the coolingsystem 202. This condenser impeller 210 is configured to pull airthrough a condenser coil to disperse heat throughout the cooling system202. The ambient air transits out of the air conditioner 202 via ambientair outlets in the lower compartment 205. A compressor of thecompartment 204 may be configured for operation in the cooling system202, acting as a pump that is configured to circulate refrigerant in theclosed-loop cooling system 202 between a condenser in compartment 204and one or more evaporator coils in compartment 208.

The air conditioner 202 further includes a first enclosure sidecompartment 206 on the upper side of the air conditioner 202. The firstenclosure side compartment 206 comprises an electrical box (refer toFIG. 3 for a detailed description of example components that may beincluded therein). This electrical box is sealed from the ambient air ofcompartments 204, 205 and provides for easy access to all controls,e.g., via removal of the top plate that encloses the first enclosureside compartment 206 from the ambient air. A digital controller 207 maybe attached to the front side of the first enclosure side compartment206, as illustrated in FIG. 2, or the digital controller 207 may beattached to the rear side of the first enclosure side compartment 206(not illustrated in FIG. 2).

The air conditioner 202 includes a second or rear enclosure sidecompartment 208, which is an elongated compartment that extends aboutthe entire length of the rectangular housing of the air conditioner 202and interfaces with the interior of the enclosure 201. This secondenclosure side compartment 208 may communicate with the first enclosureside compartment 206, such that the two compartments 206, 208 form aninverted L shaped or “7” shaped enclosure side compartment, which issealed off from the ambient side compartments 204, 205. The rear face ofthe air conditioner 202, i.e., where the second enclosure sidecompartment 208 interfaces with the enclosure 201, includes an enclosureair intake and return, as further described herein.

As illustrated in FIG. 2, the air conditioner 202 includes condensercoils in compartment 204 that are coupled to the compressor and comprisea plurality of tubes that carry refrigerant. These condenser coils areconfigured to convert refrigerant in the form of gas or vapor back intoliquid form by removing heat. Ambient air enters compartment 204 from aside air inlet (431 illustrated in FIG. 4D) to interact with thecondenser coils and ambient air exits from point(s) in compartment 205(429, 432, 433 illustrated in FIG. 4B-D).

Evaporator coils are located in compartment 208 and carry refrigerant toremove heat from enclosure air as the refrigerant evaporates. Enclosureair is circulated through the evaporator coil in compartment 208 via anevaporator impeller (illustrated at 140 of FIG. 1A) within an enclosureside compartment 208 of the cooling system. The enclosure impeller 140is provided in a nonincendive manner. Cooled enclosure air may then bereturned from compartment 208 to the enclosure 201 through a return (428illustrated in FIG. 4A).

Referring now to FIG. 3, a top view of air conditioner 202 isillustrated. Here, the first enclosure side compartment (206 of FIG. 2)is illustrated with the top cover or plate removed to reveal examplefunctional components included in the electrical box. As illustrated,the top compartment includes non-sparking, non-arcing components suchthat these components may be exposed to enclosure air without a need forpurging the compartment.

Illustrated in FIG. 3 is an upper plate 318 that secures or supports avariety of components, e.g., a toroidal transformer 311 (which may besealed or encapsulated), current limiting control transformer 312, asolid-state compressor overload relay 313, a solid-state alarm relay314, a solid-state condenser fan relay 315, a solid-state compressorrelay and evaporator impeller relay 316, an evaporator sensor (routedthrough bushing 317 and placed in second enclosure side compartment),and encapsulated (e.g., epoxy filled) condenser and evaporator fan runcapacitors, 319 a, 319 b, respectively. Compressor run capacitor 341 maylikewise be encapsulated. Each component of the upper or first enclosureside compartment (206 of FIG. 2) is non-sparking, non-arcing andtherefore safe for use in a hazardous air environment without a need topurge this or any enclosure compartment of the cooling system. Anonincendive digital controller is also provided (illustrated near thebottom in FIG. 3, although the digital controller may be located at theopposite, enclosure side of the electrical box, as further describedherein).

The component parts and connections of the first enclosure sidecompartment 206 of FIG. 2 are non-sparking, non-arcing, and they do notcombust air during normal operation. These component parts include, forexample, a compressor solid-state relay 316 operably coupled to thecompressor (provided within compartment 204 of FIG. 2) and a condenserfan/N/O alarm solid-state relay 315, which is operably coupled to thecondenser or impeller fan to control the functionality of thesecomponent parts. The electrical box may also house a sealed compressorrun capacitor 341; this compressor run capacitor 341 may be positionedfor example in the place of toroidal transformer 311, e.g., for 110V and120V implementations, and be used to aid the starting of the compressorand the compressor impeller during operation of the cooling system).Other intrinsically-safe or nonincendive components housed in theelectrical box may include the compressor overload solid-state relay 313(or an encapsulated overload), the limit controlling transformer 312,and alarm solid-state relay 314.

FIG. 3A illustrates a cross section of the first enclosure sidecompartment at section E-E of FIG. 3. As shown, the first enclosurecompartment (206 in the example of FIG. 2) may include a purge fitting322 near the rear surface of the air conditioner for a purge tube 321. Apurge tube 321 and fitting 322 are not required, as all components arenon-sparking, non-arcing, and thus do not require purging, e.g., byconducting of purge air into the first enclosure side compartment viathe purge tube 321 and exiting into the compartment via end 323.However, certain enclosure operators may wish to connect the purgefitting 322 to a purge system of the enclosure for internal compliancerules or to purge any air in the enclosure side compartments 206, 208that may be thought to remain after installation.

As illustrated in FIG. 3A, the upper plate 318 is separated from a lowerplate 324 of the first or upper enclosure side compartment. The lowerplate 324 supports the upper plate 318 and defines an air gap 325. Airfrom the enclosure (e.g., 201 of FIG. 2) that is circulated through theenclosure side compartments (e.g., 206, 208 of FIG. 2) circulates overand underneath plate 318, which is an integrated heat sink, and thecomponents supported thereon as the air conditioner operates tocirculate enclosure air therethrough. This provides additional air flowand cooling capacity to the components supported by plate 318 andpermits operation of the air conditioner unit at higher ambienttemperatures. For example, the air conditioner can operate between about−40 C to 60 C ambient temperatures.

FIG. 4 (A-D) illustrates rear, left, front and right-side views,respectively, of the example air conditioner of FIG. 2. By way ofillustration, FIG. 4A illustrates the rear side of the air conditioner,i.e., the side that faces the enclosure opening. The rear side includesan enclosure air intake 427 and return 428, through which air is drawnfrom and returned to the enclosure by an enclosure impeller (140 of FIG.1). FIG. 4B illustrates a left side view in which the air intake 427 isagain visible, as is one of three ambient air exhausts 429. FIG. 4Cillustrates a front view in which a digital controller 407 is disposed(on the front of the air conditioner) and a second ambient air exhaust432 is illustrated. Shown in FIG. 4D are an air filter 430 (e.g., a 10micron filter) and ambient air inlet 431 (co-located and covered by theair filter 430). In addition, FIG. 4D illustrates an additional, thirdambient air exhaust 433 that is covered by a diverter plate 434. Thediverter plate 434 is co-located with and covers any of the air exhausts429, 432 or 434. The diverter plate 434 is optional and can bepositioned to direct air flow through the remaining open exhaustsselected from 429, 432 or 433.

In FIG. 5 a rear view of the example air conditioner 202 of FIG. 2 isillustrated in which the interior of the lower side of the second orelongated enclosure side compartment (208 of FIG. 2) is visible. Thisillustrates the internal drain assembly 535 located behind theevaporator coil of the elongated enclosure side compartment, inside of adrain pan, which permits water to exit out of the lower or secondambient side compartment. FIG. 5 also illustrates the air intake 527 forthe enclosure air.

The drain assembly 535 of FIG. 5 is illustrated in detail in FIG. 5A.Here, it is illustrated that a trap assembly 536 secures a ball 537 thatis contained in the trap assembly 536 and is positioned on a drain tube538. The ball 537 is buoyant and as water fills the lower part of thesecond enclosure side compartment drain pan, the ball 537 transitsupward, permitting water to exit out the bottom of the conditioner 539via drain tube 538.

The drain pan holding the drain assembly 535 is configured to collectwater that is created as a by-product of the condensation process. Inone embodiment, the cooling system is configured with a condensatemanagement system including a float drain. This drain system aids inmaintaining the pressure inside a customer's enclosure.

An example method is illustrated in FIG. 6. In an embodiment, a methodincludes attaching a cooling unit to an enclosure opening and drawingheated enclosure air into evaporator and electronics compartments at601. The cooling unit, e.g., air conditioner, includes a system ofcomponents in separate compartments. For example, in the method, thecooling unit is constructed to segregate ambient and enclosure sidecompartments. The cooling unit is sealed to the enclosure opening,preventing ambient air entry via the enclosure opening. Because thecooling unit ambient and enclosure compartments are segregated, theambient air of any ambient compartment cannot enter the enclosure.Further, the enclosure compartment(s) of the cooling unit contain onlynon-sparking, non-arcing components, making the cooling unit safe foruse in a hazardous air environment. In an embodiment, the ambientcompartment(s) contain only non-sparking, non-arcing components, makingthe cooling unit safe for use in a hazardous air environment. In anembodiment, all compartments (i.e., the entire unit) contain onlynon-sparking, non-arcing components, making the cooling unit safe foruse in a hazardous air environment.

At 602, ambient air is drawn into an ambient side compartment of the airconditioner. Consequently, at 603 conditioned air is returned to theenclosure via an air outlet of the enclosure side and at 604 heatedambient air is expelled via one or more of the ambient air outlets.

In particular, enclosure air intake and return, e.g., of a rear face ofthe elongated, rear enclosure side compartment, are arranged to conductheated air from the enclosure over the cooling coils. This operationincludes conducting heated air from the enclosure over components of anelectric box, e.g., of an upper enclosure side compartment of thecooling unit having non-sparking, non-arcing components disposedtherein. Therefore, the operating includes additional internal coolingof heat generating components of the cooling unit, extending itsoperational temperature range significantly.

In various embodiments, different, fewer, or additional components maybe included. For example, in an embodiment the electrical box of thefirst enclosure side compartment 206 of FIG. 2 may comprise one or moreof an Ethernet connector, an alarm output, as well as power input andconnections. The Ethernet connector may be configured for remotecommunication and monitoring of the cooling system. Other connectors maybe included. As described, a digital controller, e.g., controller 107,can be mounted on the front or rear of the air conditioner. For example,the digital controller 107 may be mounted on the rear of the airconditioner 202 to protect it from unwanted operation. In such cases,remote control of the controller 107 may be preferable as manual accessmay be difficult.

The illustrated example air conditioner electrical box is configured for480V. However, the present disclosure is not limited to such anembodiment and it is contemplated that other configurations are withinthe scope of the present disclosure. For example, an embodiment may beconfigured for 230V operation or for 120V operation.

In an embodiment, the capacity of the air conditioning units is between1,000 BTU to 20,000 BTU, or more. Therefore, it will be appreciated thateven with the relatively small size of the air conditioner, a largecooling capacity is obtained.

It is worth noting that while specific elements are illustrated in thefigures, and a particular ordering or organization of elements or stepshas been illustrated, these are non-limiting examples. In certaincontexts, two or more elements or steps may be combined into anequivalent element or step, an element or step may be split into two ormore equivalent elements or steps, or certain elements or steps may bere-ordered or re-organized or omitted as appropriate, as the explicitillustrated examples are used only for descriptive purposes and are notto be construed as limiting.

As used herein, the singular “a” and “an” may be construed as includingthe plural “one or more” unless clearly indicated otherwise.

This disclosure has been presented for purposes of illustration anddescription but is not intended to be exhaustive or limiting. Manymodifications and variations will be apparent to those of ordinary skillin the art. The example embodiments were chosen and described in orderto explain principles and practical application, and to enable others ofordinary skill in the art to understand the disclosure for variousembodiments with various modifications as are suited to the particularuse contemplated.

Thus, although illustrative example embodiments have been describedherein with reference to the accompanying figures, it is to beunderstood that this description is not limiting and that various otherchanges and modifications may be affected therein by one skilled in theart without departing from the scope or spirit of the disclosure.

What is claimed is:
 1. A cooling unit, comprising: a housing configuredto attach to an enclosure opening in a sealed manner, wherein theenclosure houses heat generating electrical equipment; the housingcomprising: a first ambient side area comprising a compressor,condensing coils, and an ambient air intake and outlet; a firstenclosure side area situated above the first ambient side area andcomprising an electrical box that includes one or more relays and adigital controller; a second enclosure side area extending along therear side of the housing and communicating with the first enclosure sidearea, comprising an impeller, an enclosure air intake, an enclosure airreturn, and evaporator coils in fluid communication with the condensingcoils; and a second ambient side area comprising an impeller and one ormore hot air exhausts; wherein all components of the cooling unit arenon-sparking and non-arcing and the first and second enclosure sideareas do not require purging of hazardous air; and wherein the first andsecond ambient side areas are sealed off from the first and secondenclosure side areas.
 2. The cooling unit of claim 1, wherein one ormore of the components of the electrical box are sealed, nonincendive,or solid-state devices.
 3. The cooling unit of claim 1, wherein thefirst enclosure side area comprises a first plate onto which one or morecomponents of the electrical box are attached, and wherein the firstplate sits atop a second plate that seals the first enclosure side areaoff from the first ambient side area.
 4. The cooling unit of claim 3,wherein the first and second plates define an air gap into whichenclosure air circulates.
 5. The cooling unit of claim 1, wherein thehousing is rectangular in shape.
 6. The cooling unit of claim 1,comprising a filter positioned to filter air that transits through theambient air intake.
 7. The cooling unit of claim 5, wherein therectangular housing is about 11 inches in width.1
 8. The cooling unit ofclaim 7, wherein the second enclosure side area extends less than halfof the depth of the rectangular housing.
 9. The cooling unit of claim 7,wherein the one or more hot air exhausts comprise three hot air exhaustspositioned on the front, left and right sides of the rectangularhousing.
 10. The cooling unit of claim 9, comprising a diverter platethat attaches to any of the three hot air exhausts.
 11. The cooling unitof claim 1, wherein the digital controller is disposed within a rear,enclosure facing surface of the housing.
 12. The cooling unit of claim1, wherein the second enclosure side area comprises a water draintherein.
 13. The cooling unit of claim 12, wherein the water drain isdisposed in a bottom of the housing.
 14. The cooling unit of claim 13,comprising a ball and drain tube situated in an assembly.
 15. A methodof installing a closed loop cooling unit on an enclosure for hazardouslocation cooling, comprising: attaching the cooling unit to theenclosure such that an enclosure side of the cooling unit conductsheated air from the enclosure over cooling coils disposed within anelongated, rear enclosure side area of the cooling unit, which faces theenclosure; the attaching comprising arranging an enclosure air intakeand return of a rear face of the elongated, rear enclosure side area toconduct heated air from the enclosure over the cooling coils; andoperating the cooling unit to conduct heated air from the enclosure overcomponents of an electric box of an upper enclosure side area of thecooling unit having non-sparking, non-arcing components disposedtherein; wherein ambient side areas of the cooling unit are segregatedfrom the elongated, rear enclosure side area and the upper enclosureside area of the cooling unit; and wherein all components of the coolingunit are non-sparking and non-arcing, and do not require purging ofhazardous air.